A novel flexure-based vertical nanopositioning stage with large travel range

Abstract

This paper presents the design of a novel flexure-based vertical (or Z-axis) nanopositioning stage driven by a piezoelectric actuator (PZT), which is capable of executing large travel range. The proposed stage consists mainly of a hybrid displacement amplification mechanism (DAM), a motion guiding mechanism, and a decoupling mechanism. The hybrid DAM with amplification ratio of 12.1 is developed to transfer the transverse motion of the PZT actuator into the vertical motion. The motion guiding mechanism is introduced to avoid cross coupling at the output end. The decoupling mechanism can significantly reduce the cross coupling at the driving end to protect the PZT. The stiffness and dynamics of the proposed stage are improved by these mechanisms. Analytical modeling and finite element analysis (FEA) are then adopted to optimize dimensions of the stage. Finally, a prototype of the stage is fabricated and tested for verification. The results of static and dynamic tests show that the proposed stage is capable of vertical travel range of 214 μm with resolution of 8 nm, and the first two resonance frequencies are 205 Hz and 1206 Hz, respectively. Cross coupling tests under various lateral loads (0 g-1000 g) show that the maximum variances of the lateral and angular cross couplings are less than 0.78 μm and 95 μrad, respectively, indicating good decoupling capability. In addition, the low-profile structure of the stage is well suited to be used in limited vertical space.

Kinetostatic and Dynamic Modeling of Flexure-Based Compliant Mechanisms: A Survey

“…Other applications of this method can be found in the literature, such as Yeom et al [176] for an elliptic-type amplifier; Du et al [177] for a 6DOFs flexure mechanism as well as a vertical nanopositioner in Ref. [120].…”

“…6.1 Lagrange-Based Methods. Over the past three decades, Lagrange-based dynamic modeling approaches have been developed for compliant mechanisms [113][114][115][116][117][118][119][120][121][122][123][124][125][126][127][128][129][130]. Generally speaking, the reported approaches can be roughly classified into three categories, as shown in Fig.…”

“…Two books in the field of compliant mechanisms [1,97] mainly involve the kinetostatic issue. To sum up, the previous dynamic modeling of compliant mechanisms was mainly based on Lagrange's method [113][114][115][116][117][118][119][120][121][122][123][124][125][126][127][128][129][130]. In recent years, some newly dynamic modeling approaches, such as the pseudorigid-body model with mass factors [108] and the dynamic stiffness modeling method based on d'Alembert's principle [18,131,132], were developed for the dynamic analysis of compliant mechanisms.…”

“…For example, a PRBM-based dynamic model was built for parallelguided compliant mechanisms [114] based on Lagrange's equation and the dynamic equivalence. In the second category, the equivalent input/output stiffness of compliant mechanisms is first modeled by using a variety of kinetostatic methods, the dynamic model can be then formulated by calculating elastic and kinetic energies based on Lagrange's equation with motion degrees-offreedom (DOFs) as the variables, all these solutions can be classified as a lumped-parameter dynamic model [119][120][121][122][123]. The third category is termed the distributed-parameter model with finite number of DOFs [124][125][126][127][128][129][130][131][132], in which compliant mechanisms are usually discretized into several submembers and the dynamic model is established by calculating total elastic and kinetic energies.…”

Design and development of a novel monolithic compliant XY stage with centimeter travel range and high payload capacity

“…The stiffness characteristic of compliant mechanism has direct effects on the workspace, load-carrying capacity, dynamic behavior and positioning accuracy of the entire mechanism (Zhu et al, 2015). The mathematical model of SPLCM is established by Matrix of structural analysis (MSA) (Przemieniecki, 1968).…”